Biotransformation of D-limonene to carveol by an endophytic fungus Aspergillus flavus IIIMF4012

Abstract

Microbial biotransformation is an efficient process for making high-value natural products in a controlled and environment friendly manner. Bioconversion of low value monoterpenes to high value products using fungi offers an effective strategy for producing desirable products. Efficient conversion of D-limonene, a monoterpene, into carveol is reported in this study by using an endophytic fungus, Aspergillus flavus IIIMF4012, isolated from the root of Rosa damascena. By optimizing different parameters, isolated strain resulted in the hydroxylation of D-limonene to carveol effectively and the process was carried out at 1 L scale which resulted in the formation of a mixture of carveol isomers (cis- carveol 23.82%, trans- carveol 17.21%). Further, the biotransformation was scaled up in 5 L fermenter and the product was characterized by GC-MS and NMR (¹H & ¹³C). As a result, an efficient procedure was established for biotransforming a low-value molecule i.e., D-limonene into a high-value product i.e.,carveol.

Keywords:

• Biotransformation
• Rosa damascena
• Aspergillus flavus
• D-limonene
• Carveol

Acknowledgments

The authors are grateful for the financial assistance from CSIR-Aroma Mission Project (HCP-007) and Dr. Prasoon Gupta for providing his valuable insights. The manuscript bears CSIR-IIIM communication no. CSIR-IIIM/IPR/00482.

Ethical Approval

Ethical Approval is not applicable for this article.

Author contributions

NAB carried out all of the experiments and wrote the manuscript, AG and NS helped in writing of manuscript, BAL isolated and characterized the compound, HS and HK contributed in proof reading, SG helped in identification of plants and provided authenticated plant samples, VB conceptualized, coordinated, supervised the entire work and corrected the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).